1. Field of the Invention
This invention relates to a wind and rain preventing device for aluminum doors and windows, particularly to one able to tightly combine a lower frame, an inner window and an outer window together to stop strong wind and heavy rain from getting in a room and also able to quickly drain rain water out of the window grooves and having good effects of water and air tightness and sound insulation.
2. Description of the Prior Art
A conventional high-and-low stepped aluminum window 1a, as shown in FIGS. 1 and 2, includes a lower frame 10a has its topside surface formed with a high and a low step so that rain water dropping on the lower frame 10a can flow to the outside of a room. The high and the low step of the lower frame 10a are respectively provided with an inner window slide rail 100a and an outer window slide rail 101a respectively fitted thereon with an inner window 11a and an outer window 12a. The inner and the outer window slide rail 100a, 101a are respectively bored with a draining hole 102a, 103a and respectively have one side formed with an inner window groove 104a and an outer window groove 105a for draining water away. Thus, water gathered in the inner and the outer window grooves 104a, 105a can be drained away to the outside of a room through the draining holes 102a, 103a of the inner and the outer window rail 100a, 101a. In addition, the inner window 11a and the outer window 12a are respectively formed with a same window structure made of two symmetrical horizontal window frames 110a, 120a and two symmetrical vertical window frames 11a, 121a. 
The horizontal window frames 110a, 120a have their interiors respectively formed with an accommodating space 112a, 122a respectively fitted therein with a roller 113a, 123a. Thus, the inner and the outer window 11a, 12a can be slidably moved on the inner and the outer window slide rail 100a, 101a by means of the roller 113a, 123a for opening and closing. The accommodating space 112a, 122a have their lower edges abutting the opposite sides of the inner and the outer window rail 100a, 101a respectively formed with two opposite and symmetrical engage grooves 114a, 124a having their inner sides respectively inserted with a water-proof block 115a, 125a composed of an engage member 1150a, 1250a and a water-proof member 1151a, 1251a. Although the water-preventing blocks 115a, 125a are provided for hindering rain water and strong wind from getting in a room through the bottoms of the inner and the outer window 11a, 12a, yet the water-preventing members 1151a, 1251a of the water-proof blocks 115a, 125a are not strong enough to block strong wind and heavy rain. When strong wind together with pouring rain blows towards the water-proof members 1151a, 1251a of the inner and the outer window 11a, 12a, the water-proof members 1151a, 1251a are likely to be blown and moved to cause gaps between the water-prevent members 1151a, 1251a and the inner and the outer window slide rails 110a, 101a, rendering strong wind and rain able to invade in a room through the gaps.
Referring to FIGS. 3 and 4, although the inner and the outer window 11a, 12a of the conventional high-and-low stepped aluminum window 1a is provided with water-proof blocks 115a, 125a engaged in the engage grooves 114a, 124a in the lower inner side of the horizontal window frames 110a, 120a, yet such water-preventing blocks 115a, 125a are too simple in structure to block strong wind and pouring rain. Further, after the horizontal window frames 110a, 120a and the vertical window frames 111a, 121a are combined together, their joint portions may form gaps contacting with the lower frame 10a; therefore, rain water is easy to get in the lower frame 10a through the joint gaps and gathered therein, as indicated by block arrows shown in FIG. 3. Furthermore, the rain water gathered in the lower frame 10a is likely to be blown by strong wind to splash about or directly get in a room through the draining holes 102a, 103a of the inner and the outer window slide rails 100a, 101a. A waterproof block 13a composed of a block member 130a and a sheet-shaped member 131a can be fitted at central portion of the inner side of the outer window groove 105a. Thus, when the inner and the outer window 11a, 12a are in a closed condition, the gaps formed between the lower overlapping portion of the two windows 11a, 12a and the inner and the outer window slide rail 100a, 101a can be blocked and covered up by the sheet-shaped member 131a of the water-proof block 13a to prevent rain water from getting in a room, and the rain water in the outer window groove 105a can be stopped from flowing backward.
However, the block member 130a of the water-proof block 13a has no draining means, unable to carry out water draining; therefore, when rain water is blocked by the sheet-shaped member 131a and drops on the block member 130a, it will be gathered in the gaps of the sheet-shaped members 131a and impossible to be drained out quickly. Thus, when strong wind together with rain blows violently, rainwater will splash to overflow the lower frame 10a and get in a room.
A conventional flush-stepped window 2a, as shown in FIGS. 5 to 8, includes a lower frame 20a having its topside surface provided with an inner and an outer window slide rail 200a, 201a respectively assembled thereon with an inner window 21a and an outer window 22a. The conventional flush-stepped windows 2a has the same structure and the same defects as those of the conventional high-and-low stepped window 1a, although the conventional flush-stepped window 2a can be assembled and disassembled comparatively easily.
As can be understood from the above description, either the conventional high-and-low stepped windows and flat-stepped windows are unable to mutually combine the lower frame together with the inner window and the outer window tightly, likely to form gaps at the joint portions and other badly designed portions, As a result, strong wind and rain water are easy to get in a room through these gaps.